Alternative of inverter on wind energy turbine for electrification

Thursday, February 12, 2015

There are several reasons you see inverters in such heavy use in renewable energy. You have the problem of converting from one voltage level at the source, to a substantially different voltage. And the source voltage can vary substantially. To do this, you must employ some type of alternating-or-pulsed input to a conversion system. And, that system must include an inductive device. I.e., a coil or transformer. A dc up-conversion would be almost impossible otherwise, and a dc down-conversion would be very inefficient. (You can do voltage level conversion using diodes and capacitors, but that approach is not practical for large currents and a variable input voltage.) An inductor has the property where V=Ldi/dt, which means it will provide any output voltage you desire, if you provide the needed amount of inductance with a current that you change at the required rate. Well, we call these devices inverters. Or, you can use coupled inductors, which of course is simply a transformer.

I do marine electronics and a lot of small standalone systems, but in boats there is not the room to add enough batteries to make it practical, Instead I have been sticking to 12 volt systems , It's the most common and often available free or cheap (used auto components) led lighting and communications make this a good way to go if heavy appliances are not used, The cost of large batteries and their limited life span makes for high maintenance and cost.

An alternative would be to control the rpm's of your turbine with variable pitch blades, such that your turbine always turns at the same rate, but you would severely limit the power you can get out of your turbine using this approach. You could also design your generator with windings you could switch in and out, but this would be impractical and costly.

In summary, inverters are the only practical solution. I'm afraid you just have to pay the price. Fortunately, inverter technology is mature and reliable.